Nikki Haley, U.S. Ambassador to the United Nations, announced her resignation on Tuesday.

President Trump, who referred to Haley as a “fantastic person” in a joint press conference following the announcement, said Haley first indicated that she planned to leave six months ago. Her tenure as America’s ambassador to the U.N. will conclude at the end of the year.

President Trump credited Haley with helping the administration tackle many significant challenges. He put particular emphasis on what was, until recently, considered a nuclear crisis in North Korea. The president went on to say that he hopes to see Haley join his administration again in a different role sometime in the future—Haley chuckled at this remark.

An accomplished politician herself, Haley previously served as the governor of South Carolina and has gained significant notoriety in the Republican Party since assuming her U.N. duties.  Some credit Haley’s popularity to her no-nonsense personality and willingness to challenge President Trump when she felt it was appropriate. Some have even gone as far as to suggest that she could potentially challenge Trump for the party’s nomination in the 2020 presidential election.